(19)

(11)

EP 0 553 328 A1

(12)

(43) Date of publication: 04.08.1993 Bulletin 1993/31 (21) Application number: 92917566.0 (22) Date of filing: 19.08.1992

(51) International Patent Classification (IPC):  B27N 3/ 00( . ) E04B 1/ 76( . ) D21H 11/ 00( . ) (86) International application number: PCT/CA1992/000355 (87) International publication number: WO 1993/004239 (04.03.1993 Gazette 1993/06)

(84) Designated Contracting States: AT BE CH DE DK FR GB IT LI NL SE (30) Priority: 21.08.1991 CA 19912050132 (71) Applicant: NATIONAL RESEARCH COUNCIL CANADA Ottawa Ontario K1A OR6 (CA)	(72) Inventor: BOMBERG, Mark Gloucester, Ontario K1J 6B5 (CA) (74) Representative: Copp, David Christopher  Dummett Copp & Co. 25 The Square Martlesham Heath Ipswich Suffolk IP5 7SL Ipswich Suffolk IP5 7SL (GB)